Semiconductor integrated circuits (ICs) are fabricated by a variety of processes for patterning, deposition, removal, and modification. The processes are performed in various semiconductor process tools. A typical semiconductor process tool includes a chamber where one or more substrates are treated by processing materials. The chamber is usually connected to exhaust pipes to remove excess processing materials and by-products of the processes from the chamber. With time, the exhaust pipes can become clogged by the excess processing materials and by-products. For example, excess photoresist from a photoresist coater crystalizes and clogs the exhaust pipe of the photoresist coater. As a result of a clogged exhaust pipe, thickness of a photoresist layer on a substrate processed by the photoresist coater becomes unstable and negatively affects process quality. Additionally, excess processing materials and by-products clogged in the exhaust pipe may cause corrosion of the exhaust pipe.
Accordingly, there is a need to solve the above deficiencies.